Not Applicable
This invention relates to archery bows and accessories thereof, and more particularly to a damping device or devices to be incorporated into or attached to the bow handle, risers limbs, limb cups or accessories to absorb excess energy thereby reducing hand shock, noise and bow vibration, which makes the bow smother and quieter to shoot.
Everyone is familiar with the archery bow and arrow. The bow is a simple mechanical device used to store energy derived from the archer during the drawing of the bow and then when the archer looses the bow string the bows energy is rapidly released. The greater portion of this energy goes into the launching of the arrow and most of the remainder finds its way back into the bow with the excess resulting in noise or is simply lost in the transfer process. Some of the energy that goes back into the bow returns it to its original undrawn state but much of it goes into excessive movement of various bow components resulting in bow hand shock and system vibrations.
Over the years archery manufactures have attempted to make the bow more efficient, and in some ways they have succeeded. The compound bow is an example of the modern manufactures success in being able to increase the amount of energy that a bow can store. Some modem compound bows store almost 50% more energy per peak pound of draw weight than the longbows of years past. The basic premise being that the more energy stored the more energy one has available to launch the arrow and the result will be greater and greater arrow launch velocities. To some extent this has become true and arrow initial velocities for bow hunters have increased over the last couple of decades. Along with bows that are capable of storing energy more efficiently, the quest for higher arrow velocities has been further augmented by the fact that lighter mass weight arrows have greater launch velocities than do heavier mass weight arrows. Arrow manufactures in the last two decades have taken advantage of the availability of higher strength materials and made lighter and lighter mass weight arrows available.
The result is that today""s bows are storing more energy and are being used to launch lighter and lighter weight arrows. The problem arises from the fact that the amount of energy that a given bow can transfer to an arrow is directly proportional to the weight of the arrow being shot. The overall mechanical efficiency of the bow is determined in the usual fashion in that we look at the ratio of the energy coming out of the system divided by the energy that was put into the system. In this case we have the kinetic energy in the arrow at launch divided by the energy put into the bow by the archer prior to arrow launch. In this manner it is easily verifiable that bows in general can have efficiencies of nearly 90% when shooting very heavy weight arrows and the same bow can exhibit efficiencies in the lower 60 percentile when shooting very light weight arrows. The result is that a bow shooting heavy weight arrows imparts most of its stored energy to the arrow and after launch the bow must absorb only 10% of the original stored energy. On the other hand if the same bow were to shoot very light weight arrows it would have to absorb up to 40% of the original stored energy after each launch.
A number of the compound bows being offered today can store as much as 100 foot pounds of energy, therefore it is conceivable that such a bow shooting a very light weight arrow could have to absorb up to almost 40 foot pounds of energy after each arrow launch. This excess energy trapped in the bow often results in a great deal of bow shock and vibration which is not only unpleasant to the archer but also takes its toll on the bows components and the accessories mounted to the bow.
Some manufactures have tried to address the problem of this residual energy by using after market shock absorbing stabilizers and several patents have been issued for such devices (e.g. U.S. Pat. Nos. 5,016,602 and 5,411,009). These devices tend to be effective only along the axis on which they are mounted and the degree of damping that they provide is generally proportional to the amount of weight that they add to the system. The proposed damper is designed to be multi-axial in its ability to absorb and dissipate excess energy and in comparison it adds much less weight making it much more effective than previous dampers.
Other inventions which may be utilized with, or which may be otherwise relevant to, the present invention are disclosed in the following concurrently filed and commonly assigned applications: U.S. Application entitled IMPROVED ELASTICALLY MOUNTED COUNTER WEIGHT, application Ser. No. 09/502149, filed Feb. 11, 2000; U.S. Application entitled DUAL FEED PIVOTING FEED-OUT, application Ser. No. 09/502643, filed Feb. 11, 2000; U.S. Application entitled ROUND WHEEL CAM, application Ser. No. 09/502354, filed Feb. 11, 2000; U.S. Application entitled ARCHERY BOW WITH BOW STRING COPLANAR WITH THE LONGITUDINAL AXIS OF THE BOW HANDLE, application Ser. No. 09/502917, filed Feb. 11, 2000; and U.S. Application entitled LEVEL NOCKING POINT TRAVEL CAM application Ser. No. 09/502152, filed Feb. 11, 2000.
All of the references contained herein, including the co-pending Applications listed above, are respectively incorporated in their entirety herein by reference.
The present invention is directed to a damper for reducing or dissipating energy. Specifically, the present invention addresses the problem of the excess energy that the bow is unable to transfer to the arrow during each shot by providing the bow with one or more energy-absorbing dampers. The present damper may be designed to be retrofitted to or be originally equipped upon any part of the handle, risers, limbs, limb cups, or other parts of the bow. The present damper may dissipate 20% or more of the excess energy created by the recoil of a the bow during and subsequent to shooting of the bow. This dissipation of energy reduces vibration making the shooting of the bow more pleasant and resulting in a quieter bow with less damage to bow components and accessories. One or more of the present dampers may be incorporated or retrofitted to any type of bow including modern compound bows, recurve bows, long bow, and even cross-bows.